Outdoor Unit Does Not Operate - Mitsubishi Electric MXZ-3C54VA Service Manual

• When unit cannot operate neither by the remote controller nor by EMERGENCY OPERATION switch.
Indoor unit does not operate.
• When OPERATION INDICATOR lamp flashes ON and OFF every 0.5-second.

Outdoor unit does not operate.

How to check mis-wiring and serial signal error (when outdoor unit does not work)
LED indication
for communication status
Communication status is indicated
by the LED.
Unit status
Blinking: normal communication
Lighting: abnormal communication or
not connected
Pattern 1 and 2 is repeatedly displayed
alternately. Each pattern is displayed for
15 seconds.
NOTE: "Lighting" in the table below does not
indicate abnormal communication.
MXZ-3C54VA MXZ-3C68VA
MXZ-4C71VA
Outdoor electronic control P.C. board
(Parts side)
LED3 LED2 LED1
Blinking
Pattern
LED 3 LED 2
Unit B
1 Lighting
status
Unit D
2
Goes out
status
MXZ-4C80VA MXZ-5C100VA
Outdoor electronic control P.C. board
(Parts side)
LED1 LED2 LED3
Blinking
Pattern
LED 1 LED 2
Unit A Unit B
1
status status
Unit D Unit E
2
status status
MXZ-6C120VA
Outdoor control P.C. board
LED3
Blinking
LED2
LED1
Pattern LED 1 LED 2
Unit A Unit B
1
status status
Unit C
Unit D
2
status
status
Unit E Unit F
3
status
status
A
· Turn OFF inverter-controlled lighting
equipment.
· Turn OFF the power supply and
turn ON again.
· Press EMERGENCY OPERATION
switch.
· Reinstall
either the
unit or the
light away
from each
Is serial signal
No
other.
error indicated
· Attach a filter
6 minutes later?
on remote
control
receiving
section of
Yes
the indoor
unit.
B
Turn OFF the power supply.
Is there rated voltage in
the power supply?
Turn ON the power supply.
Is there rated voltage between
outdoor terminal block S1 and
S2?
Press EMERGENCY OPERATION switch once.
Does the left lamp of OPERATION
INDICATOR lamp light up?
<Confirmation of the power to the indoor unit>
Is serial signal error indicated 6 minutes later?
LED 1
Unit A
status
Unit C
status
Turn OFF the power supply.
Check once more if the indoor/outdoor
connecting wire is not miswiring.
B
Short-circuit outdoor terminal block S2 and
S3.
1
LED 3
Unit C
status
Goes out
Turn ON the power supply.
Does the LED on the the outdoor electronic
control P.C. board or the outdoor control P.C.
board repeat "3.6-second-OFF and
0.8-second-ON quick blinking"?
LED 3
Lighting
Turn OFF the power supply.
Goes out
Remove the short-circuit between
outdoor terminal block S2 and S3.
Blinking
Turn ON the power supply.
Is there amplitude of 10 to 20V DC
between outdoor terminal block S2
and S3? <Confirmation of serial
signal>
Is there rated voltage between
indoor terminal block S1 and S2?
<Confirmation of power voltage>
Replace the indoor electronic control P.C. board.
Be sure to release the failure-mode
recall function after checking.
Refer to indoor unit service manual.
No
Check the power
supply.
Yes
No
Check the wiring.
Yes
No
Yes
No
Yes
A
1. Miswiring may damage indoor electronic control
P.C. board during the operation.
Be sure to confirm the wiring is correct before the
operation starts.
No
(Lighted
or
not lighted)
Yes
No
Yes
Is there any error of the
indoor/outdoor connecting wire,
such as the damage of the wire,
intermediate connection, poor
No
contact to the terminal block?
Yes
65
Is there any miswiring,
poor contact, or wire
Yes
disconnection of the Correct them.
indoor/outdoor
connecting wire?
No
Replace the outdoor electronic control P.C.
board or the outdoor control P.C. board.
2
2 Be careful of residual
voltage of smoothing capacitor.
Replace the
Yes
indoor/outdoor
connecting wire.
No